Multi-unit sheet-fed printing machine



Jan. 15, 1963 E.TAG| |AsAccH1 3,073,997

MULTI-UNIT SHEET FED PRINTING MACHINE Filed Aug. 12, 1959 2 Sheets-Sheet l Jan. 15, 1963 E. TAGLTAsAccHl 3,073,997

MULTI-UNIT SHEET FED PRINTING MACHINE Filed Aug. 12. 1959 2 Sheets-Sheet 2 b T W3 FROMF ,953 25T TH /24 AMPLIFIER 3 FROMSOOROEOF REFERENCE ROTTNTTAL TOOOMOTOR NT2 RECTTRER y ,f r TO Oc MOTOR MT GENERATOR Dm AMRLRER 56,?

REOTTRER c a TOOlFFERENTTAL f TOMFFIRENTML KV l OONTROLMNO C'Pv Rega CONTROLMNO c5?" FRO'M MOTOR No.2 FROM (FROM MOTOR N05 PHQQCELL PHOTOCELL PHOTOCELL PHOTOCELL C 3 E clu c25 c2u OVENTOE S, SLT-WMI (Ama-mnd Uited States Patent 3,073,997 MULTI-UNIT SHEET-FED PRINTING MACHHNE Ercole Tagliasacchi, Milan, Italy, assignor to Gllicine Meccaniche Cigardi S.p.A.-0.M.C.S.A., Milan, Italy, a corporation of Italy Filed Aug. 12, 1959, Ser. No. 833,201 Claims priority, application Italy Aug. 18, 1958 6 Claims. (Cl. S18-85) This invention generally relates to rotary printing machines or presses of the type including a sheet-feeding mechanism adapted to successively feed sheets to be printed, a plurality of printing rotary units each provided with inking means, transfer and impression cylinders adapted to offset one-color printing on the successively fed sheets `and a printed sheets piling up mechanism adapted to receive the sheets conveyed off the last one of said printing units, upon multi-color printing of said sheets in the passage thereof through the various units.

It is known to those skilled in the art to which invention appertains that multi-color printing machines of the type referred to above require the provision of linking means adapted to phasedly interconnect the various units in proper registered relationship for having the corresponding various colors print on keach sheet which is caused to successively pass through the said various units.

According to current knowledge, in the multi-unit printing machines heretofore produced the various printing thereof are mechanically interconnected, namely by means of gear means provided with registering devices. Such mechanisms are subject to several objections either in view of inertial phenomena which lead to misphasing of the various rotary elements throughout the assembly at the various service rotary speeds at which the machine may be operated, and in view of the unavoidable plays occurring in the gearing and in other linking devices of mechanical character.

lt is therefore a principal object of this invention to provide a new and advantageous multi-unit printing machine of the character referred to above, wherein the various one-color printing units thereof are phasedly interconnected by electrical means not subject to inertial phenomena and to wearing out of elements thereof, and wherein the most desirable accurate register of the several elements of the assembly is ensured.

Another object of this invention is to provide a new and advantageous multi-unit printing machine wherein the various units are subject to independent and selfacting register means adapted to control the phase relationship of the rotary elements either at any rotary speed included in the service field of the assembly and when the said elements are accelerated up to their desired service speed.

A further object of this invention is to provide, in a multi-unit printing assembly as above, including a plurality of one-color printing units each one of which is driven by its own parent variable-speed electric motor, an electric coupling circuitry adapted to level the speed of one or more motors to the speed of another motor of the assembly, namely `of the first or entrance unit driving motor.

A still other object of this invention is to provide a new and advantageous multi-color printing assembly as above, including rotary elements rotationally coupled to rotating members of adjacent units and provided with phase defining marks, photoelectric cells positioned to generate impulses as the said marks pass in front thereof, an electric motor controlled mechanical differential in the transmission means drivingly connecting the cylinders of one of said units to its parent driving motor, and amplifying and integrator means having an inlet connected to said cells and an outlet connected to said differential controlling motor for phasedly adjusting the said one unit to the phase of the said adjacent unit as a function of the time relationship of the said impulses.

Other objects and advantages of the invention are in part obvious and in part will be made apparent as this description proceeds, and the features which are considered as characteristic of the invention will be in particular set forth in the appended claims. The invention itself, however, both as to its construction and to its mode of operation, .will become best apparent from the following detailed description of a preferred form of embodiment thereof, when taken in conjunction with the accompanying drawing, forming an essential component of this disclosure.

In the drawings:

FIGURE 1 is a diagrammatical side elevational View of a printing machine of the above type, including three printing units which may be advantageously phasedly correlated according to the invention;

FIGURE 2 is a somewhat simplified plan view of the said units together with various ancillary driving and phase controlling devices of the invention;

FIGURE 3 is a diagrammatical perspective view of the photoelectric coupling of two adjacent units of the assembly; and

FIGURE 4 illustrates the circuitry, in block form.

Referring now to the drawings, wherein like characters and reference numerals refer to like parts and elements throughout the several figures:

In the form of embodiment shown, the machine is designed for three-color printing of sheets successively fed by a conventionally constructed feeding device 1 (FIG. l) in a first one-color printing unit 2, followed by a second and by a third printing units 3 and 4, respectively, wherein the sheets are caused to receive differently colored printings. The three-color print sheets are then delivered and piled up in a conventionally constructed piling and delivery device 5.

According to current knowledge, each printing unit may be provided with inking rollers 6, wetting rollers 7, a plate cylinder 8, a transfer cylinder 9 and an impression cylinder 9', the said rollers and cylinders being diagrammatically indicated and referred in the rst unit 2 in FIG. 1 only, for simplicitys sake. Further according to current knowledge, the last or delivery cylinder of each unit is adapted to transfer the sheets to the first or inlet cylinder of the subsequent unit.

As shown in FIG. 2, the delivery cylinder RIU of the first unit 2 is driven by a variable speed D.C. fed motor Mtl, through a transmission Rdl. Conventionally con- Vstructed gear means 10 are made use of for drivingly connecting the several other cylinders and rollers of same unit to the said delivery cylinder and likewise the various rotary members of other units are geared to the parent delivery cylinder of the respective unit. No mechanical linking however exists between adjacent units, according to the invention.

The delivery cylinder RZU of the second unit is at its turn driven by a variable speed D.C. fed motor Mt2 through a transmission RdZ and a diiferential DfZ controlled by a 3-phase control motor MC2. Such transmission and motor controlled differential will be not shown and described in details, as appertaining to current knowledge in the art to which this invention appertains.

Likewise the delivery cylinder RSU of third unit is driven by a variable speed D.C. motor Mt, through a transmission Rd3 and a differential Df3, controlled by a S-phase motor Mc3.

In FIG. 2, R'ZE and R313 indicate the inlet cylinders of the second and respectively of the third printing unit, the said cylinders being designed to receive the partially printed sheets from the delivery cylinders R1U and respectively RZU of the iirst and respectively of the second unit.

The said variable speed D.C. fed motors Mtl, MIZ and .Mt3 are drivingly connected to speed-metering generators Drl and respectively DIZ and Dt3. Preferably, said generators are axially connected to the shaft of the respective parent motor and adapted to provide an output which is representative of the speed at which the respective parent motor runs.

The said D.C. motors Mtl, MtZ and Mt3 are fed by D.C. generators D1 and respectively D2 and D3 (FIG. 4). The said generators D1 and D2 are driven by an asynchronous three-phate motor Mal while the third generator D3 is driven by a separate three-phase motor MaZ. Said motors Mal and MrzZ are connected by a suitable threephase line L to a suitable source of 3-phase A.C. current (not shown).

As shown in FIG. 2, the delivery cylinders RIU and RZU and the inlet cylinders RZE and RSE of the respectively subsequent unit are connected to 3-phase alternators SG1 and SGZ and respectively CTZ and CTS. Said symbols are representative for synchro-generator and respectively for control-transformer in view of the respective mode of operation in the system of the invention. The alternators include in each pairs of said alternators SG1 and CTZ and respectively SGZ and CTS, appertaining to adjacent units, are electrically coupled together, namely said alternators are provided with series-connected coils. As indicated with respect to the first pair SG1 and CTZ only, the rst alternator of the pair (i.e. alternator SG1) is provided with an exciting coil connected to feeding circuit DC while the output of second alternator of the pair (i.e. CTZ) is connected to an output circuit OCZ.

As shown in FIG. 4, a potentiometer P is connected to a D.C. source; a reference potential Vr, to be selected according to the operation requirement, may be obtained from said potentiometer P and the said reference potential Vr is caused to be opposed by a potential coming from the metering generator Dt1. The difference between the said reference potential and the said metering potential (difference which is of relatively small amplitude), upon its amplilication in a suitable amplifier Ecl, preferably provided with thyratrons, is made use of for controlling, by means of a circuit 11, the field coiling of the generator D1. The speed of motor Mtl is therefore a function of and controlled by the said reference potential Vr.

For making the speed of the second motor MtZ in strict dependency of the speed of motor Mtl, to the said reference potential Vr is opposed, in addition to the metering potential of metering generator D22, a potential derived by a rectifier DmZ, this latter potential being derived, as to its amplitude, direction and phase, by the slip existing between the alternators SG1 and CT 2 of the iirst pair of the coupled pairs, the said rectier being connected to the output circuit OCZ of said alternator CTZ (FIG. 2) of the pair. Such difference of potentials upon amplification thereof in Ec2 controls, through the circuit 12, the second generator DZ.

A likewise mode of operation is made use of for making the speed of third motor Mt3 is strict dependency of the iirst motor Mtl, by proper corresponding application of the potential derived from the pair of alternators SGZ and GT3.

For ensuring a very strict phase relationship between the rotating elements of the adjacent printing units, the delivery cylinders of the first and of the second unit and the inlet cylinders of second and of third unit are drivingly connected to disks provided with photoelectrically controlled marks. Such disks are preferably keyed to the shafts of respective cylinders. In FIG. 3 there is diagrammatically shown disks 14 and 15, provided with marks 14' and 15', respectively, and which are supposed to be connected to cylinders RIU and RZB, respectively.

A source of light, say a lamp 16 (FIG. 3') illuminates both said disks and it is so positioned that a beam of light is caused to strike on photoelectric cells C1U and CZE as the marks 14' and respectively 15 pass in a definite position within the respective circular path thereof. A corresponding pair of photoelectric cells CZU and CSE (FIG. 2) is responsive to the passage of corresponding marks borne by like disks driven by delivery cylinder RZU and respectively by the inlet cylinder R3E of second and respectively of third printing unit.

The said photoelectric cells are adapted to produce signals in form of impulses of sharp rising front wave-form as a beam of light, coming from the passing marks, 14 and 15 for example, strikes thereon. Such impulses are therefore strictly representative of the time of passage of said marks and consequently of the phase at which the rotary elements of the adjacent printing units rotate.

The said pairs of cells are connected to amplifier A1U and AZE and respectively to ampliiiers AZU and ASE wherein their impulses are ampliiied and then to integrators llU and IZE and respectively IZU and 13E connected to the metering generators of the parent unit and to relays 17 and 18 and respectively 19 and Ztl. By means of conductors Z1 and Z2 (FIGS. Z and 4) the pairs of relays 1'7 and 18 and respectively 19 and Ztl are connected to the dilferential controlling motors MC2 and respectively M03 of second and respectively of third unit.

The said integrator means (conventionally constructed) are designed to integrate `the .metering potential in the time interval which may exist between the passages of marks appertaining to the same pair of disks of adjacent units, and, if such interval exists, the output of the integrators is therefore representative of the amplitude and of the direction of said interval, i.e. if one passage of a given mark precedes or succeeds the other mark (on the other disc of the pair) in respect to the photocells of said -pair of discs.

It will be therefore readily understood that the output of said integrators is capable of controlling the operation and the direction of rotation of the said differential controlling motors McZ and Mc3 until such interval is reduced to zero, that is until the desired strict time and phase relationship between adjacent printing units is positively restored.

The control of speed and of phase of the various subsequent units in respect to the first printing unit ensures the correct synchronism of operation of -the various units too. In fact, if the reference potential Vr for the motor Mtl is caused to stop, the other motors M12 and MIS would stop in the correct phase relation only, i.e. as soon as the potentials of the outputs of the rectiiiers DmZ and Dn13 are also reduced to Zero.

While the invention has been described and shown but in one form of embodiment thereof, it is not limited to 'the very details shown. For example, the invention might be advantageously associated with printing machines including four or more printing units, by providing suitable additional circuitry equivalent to that described and operating responsive to one reference potential Vr existing between conductors Z3 and 24 (FIG. 4).

Provided that no mechanical links exists between the adjacent units, in the case of multi-color machines having a substantial number of printing units, the desired speed and phase relationship between the subsequent pairs of adjacent units will be ensured simply by causing the marks borne by the respective rotating disks to be synchronously detected by the respective photoelectric cells.

Obviously, the arrangement of the present invention may be advantageously used with machines having two printing units, too. Such two-color press may be easily conceived by supposing the machine of FIG. 2 as not provided with its third unit and without the electric and photoelectric connections existing between said third unit and the preceding one.

It is therefore believed to be evident that the present invention includes various advantageous features, and it will be understood too that each of the new features described and any combination thereof may also find useful application in other types of multi-unit printing machines or apparatus differing from the one described.

Without further analysis the foregoing will so fully 1reveal the gist of this invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of this invention and, therefore, such adaptations should and are intended to be comprehended within the spirit and meaning of equivalents of the invention, as defined in and by the appended claims.

Having thus described the invention and the mode of making use thereof, what is claimed as new and desired to be protected by Letters Patent is:

l. A circuit arrangement for the synchronization and speed control of rotating members, comprising, in combination, first and second rotating members; a first driving motor coupled to and driving said first rotating inember; a second driving motor coupled to and driving said second ro-tating member; means for providing a first control voltage having a magnitude proportional to the angular velocity of said first driving motor; means for providing a second control voltage having a magnitude proportional to the angular velocity of said second driving motor; means for providing a reference voltage of selected magnitude; means for controlling the angular velocity of said first driving motor in accordance with a difference in magnitude between said first control voltage and said reference voltage thereby controlling the angular velocity of said first rotating member; means for controlling the angular velocity of said second driving motor in accordance with a difference in magnitude between said second control voltage and said reference voltage thereby controlling the angular velocity of said second rotating member; means for controlling the angular velocity of one of said first and second driving motors in accordance with a difference in magnitude between the angular velocity of said first driving motor and the angular velocity of said second driving motor; thereby controlling the angular velocity o-f a corresponding one of said first and second rotating members; and means for controlling the instantaneous angular position of one of said first and second rotating members in accordance with a difference in magnitude between the instantaneous angular position of said first rotating member and the instantaneous angular position of said second rotating member thereby synchronizing said first and second rotating members.

2. A circuit arrangement for the synchronization and speed control of rotating members comprising, in combination, a first rotating member; a first driving motor; first transmission means including a first differential adapted to be controlled by a motor and coupling said first rotating mem-ber to said first driving motor, said first differential having an input coupled to said first driving motor and an output coupled to said first rotating member; a first differential control motor coupled to and controlling the instantaneous angular position of the input of the first differential of said first transmission means in relation to the output thereof; a second rotating member; a second driving motor; second transmission means including a second difierental adapted to be controlled by a motor and coupling said second rotating member to said second driving motor, said second differential having an input coupled to said second driving motor and an output coupled to said second rotating member; a second differential control motor coupled to and controlling the instantaneous angular position of the input of the second differential of said second transmission means in relation to the output thereof; a first generator connected to and energizing said first driving motor; a second generator connected to and energizing said second driving motor; first speed indicating means for providing a first control voltage having a magnitude proportional to the angular velocity of said first driving motor; second speed indicating means for providing a second control voltage having a magnitude proportional to the angular velocity of said second driving motor; means for providing a reference voltage of selected magnitude; first comparing means for comparing said first control voltage and said reference voltage for producing a first resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said first control voltage and the said reference voltave; first control means for applying said first resultant speed control voltage to said first generator so as to control the energization and angular velocity of said first driving motor thereby controlling the angular velocity of said first rotating member; second comparing means for comparing said second control voltage and said reference voltage for producing a second resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said second control voltage and the said reference voltage; second control means for applying said second resultant speed control voltage to said second generator so as to control the energization and angular velocity of said second driving motor thereby controlling the angular velocity of said second rotating member; third speed indicating means for providing a third control voltage having a magnitude proportional to the angular velocity of said first rotating member; fourth speed indicating means for providing a fourth control voltage having a magnitude proportional to the angular velocity of said second rotating member; third comparing means for comparing said third control voltage and said fourth control voltage for producing a third resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said third control voltage and the said fourth control voltage; third control means for applying said third resultant speed control voltage to one of said first and second generators so as to control the energization and angular velocity of the corresponding one of said first and second driving motors thereby controlling the angular velocity of a corresponding one of said first and second rotating members; first angular position indicating means for providing a fifth control voltage having a magnitude proportional to the instantaneous angular position of said first rotating member; second angular position indicating means for providing a sixth control voltage having a magnitude proportional to the instantaneous angular position of said second rotating member; fourth comparing means for comparing said fifth control voltage and said sixth control voltage for producing a first resultant synchronization control voltage having a magnitude proportional to a difference in magnitude between the said fifth control voltage and the said sixth control voltage; and fonrth control means for applying said first resultant synchronization control voltage to one of said first and second differential control motors so as to control the instantaneous angular position of the input of the differential controlled by said one of said first and second differential control motors in rela-tion to the output thereof so as to control the instantaneous angular position of the corresponding one of said first and second rotating members in a manner whereby the said first and second rotating members are maintained in synchronism.

3. A circuit arrangement for the synchronization and speed control of rotating members comprising, in combination, a first rotating member; a first D.C. driving motor; first transmission means including a first difierential adapted to be controlled by a motor and coupling said first rotating member to said first driving motor, said first `differential having an input coupled to said first driving motor and an output coupled to said first rotating member; a first differential control motor coupled to and controlling the instantaneous angular position of the input of the first differential of said first transmission means in relation to the output thereof; a second rotatt? ing member; a second DC. driving motor; second transmission means including a second differential adapted to be controlled by a mo-tor and coupling said second rotating member to said second driving motor, said second differential having an input coupled to said second driving motor and an output coupled to said second rotating member; a second differential control motor coupled to and controlling the instantaneous angular position of the input of the second differential of said second transmission means in relation to the output thereof; a first DC. generator connected to and energizing said first driving motor; a first AC. motor coupled to and driving said first D.C. generator; a second DC. generator connected to and energizing said second driving motor; a second AC. motor coupled to and driving said second DC. generator; first speed indicating means for providing first control voltage having a magnitude proportional; to the angular velocity of said first driving motor; second speed indicating means for providing a second control voltage having a magnitude proportional to the angular velocity of said second driving motor; means for providing a reference voltage of selected magnitude; first comparing means for comparing said first control voltage and said reference voltage for producing a first resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said first control voltage and the said reference voltage; first control means for applying said first resultant speed control voltage to said rst Igenerator so as to control the energization and angular velocity of said first driving motor thereby controlling the angular velocity of said first rotating member; second comparing means for comparing said second control voltage and said reference voltage for producing a second resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said second control voltage and the said reference voltage; second control means for applying said second resultant speed control voltage to said second generator so as to ycontrol the energization land angular velocity of said second driving motor thereby controlling the an gular velocity of said second rotating member; third speed indicating means for providing a third control voltage having a magnitude proportional to the angular veio` city of said first rotating member; fourth speed indicating means for providing a fourth control voltage having a magnitude proportional to the angular velocity of said second rotating member; third comparing means for comparing said third control voltage and said fourth control voltage for producing a third resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said third control voltage and the said fourth control voltage; third control means for applying said third resultant speed control voltage to one of said first and second generators so as to control the energization and angular velocity of the corresponding one of said first and second driving motors thereby controlling the angular velocity of a corresponding one of said first and second rotating members; first angular position indicating means for providing a fifth control voltage having a magnitude proportional to the instantaneous angular position of said first rotating member; second angular position indicating means for providing a sixth control voltage having a magnitude proportional to the instantaneous angular position of said second rotating member; fourth comparing means for comparing said fifth control voltage and said sixth control voltage for producing a first resultant synchronization control voltage having a magnitude proportional to a difference in magnitude between the said fifth control voltage and the said sixth control voltage; and fourth control means for applying said first resultant synchronization control voltage to one of said first and second differential con- -trol motors so as to control the instantaneous angular position of the input of the differential controlled by said one of said first and second differential control motors in relation to the output thereof so as to control the instantaneous angular position of the corresponding one of said first and second rotating members in a manner whereby the said first YandV second rotating members are maintained in synchronism.

4. A circuit arrangement for the synchronization and speed control of rotating members comprising, in combination, a first rotating member; a first DC. driving motor; first transmission means including a first differ'- ential adapted to be controlled by a motor and coupling said first rotating member to said first driving motor, said first differential having an input coupled to said first driving motor and an output coupled to said first rotating member; a first differential control motor coupled to and controlling the instantaneous angular position of the input of the first differential of said first transmission means in relation to the output thereof; a second rotating member; a second DC. driving motor; second transmission means including a second differential adapted to be controlled by a motor and coupling said second rotating member to said second driving motor, said second differential having an input coupled to said second driving motor and an output coupled to said second rotating member; a second differential control motor coupled to and controlling the instantaneous angular position of the input of the second differential of said second transmission means in relation to the output thereof; a first D C. generator connected to and energizing said first driving motor; a first AC. motor coupled to said first D C. generator; a second D C. generator connected to and energizing said second driving motor; a second AC. motor coupled to said second D.C. generator; first speed indicating means for providing a first control voltage having a magnitude proportional to the angular velocity of said first driving motor; second speed indicating means for providing a second control voltage having a magnitude proportional to the angular velocity of said second driving motor; means for providing a reference voltage of selected magnitude; first comparing means for comparing said first control voltage and said reference voltage for producing a first resultant speed control Voltage having a magnitude proportional to a difference in magnitude between the said first control voltage and the said reference voltage; first control means for applying said first resultant speed control voltage to said first generator so as to control the euergization and angular velocity of said first driving motor thereby con trolling the angular velocity of said first rotating member; second comparing means for comparing said second control voltage and said reference voltage for producing a second resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said second control voltage and the said reference voltage; second control means for applying said second resultant speed control voltage to said second generator so as to control the energization and angular velocity of said second driving motor thereby controlling the angular velocity of said second rotating member; third speed indicating means for providing a third control voltage having a magnitude proportional to the angular velocity of said first rotating member; fourth speed indicating means for providing a fourth control voltage having a magnitude proportional to the angular velocity of said second rotating member; third comparing means for comparing said third control voltage and said fourth control voltage for producing a third resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said third control voltage and the said fourth control voltage; third control means for applying said third resultant speed control voltage to one of said first and second generators so as to control the energization and angular velocity of the corresponding one of said first and second driving motors thereby controlling the angular velocity of a corresponding one of said first and second rotating members; first angular position indicating means for providing a fifth 9 control voltage having a magnitude proportional to the instantaneous angular position of said first rotating member, said first angular position indicating means comprising a first disc adapted to rotate synchronously with said first rotating member and having an angular position indicating marking thereon, first photosensitive means, and means for impinging light upon said first disc in a manner whereby light is refiected from said last-mentioned angular position indicating marking to said first photo- Sensitive means; second angular position indicating means for providing a sixth control voltage having a magnitude proportional to the instantaneous angular position of said second rotating member, said second angular position indicating means comprising a second disc adapted to rotate synchronously with said second rotating member and having an angular position indicating marking thereon, second photosensitive means, and means for impinging light upon said second disc in a manner whereby light is refiected from said last-mentioned angular position indicating marking to said second photosensitive means; fourth comparing means for comparing said fifth control voltage and said sixth control voltage for producing a first resultant synchronization control voltage having a magnitude proportional to a difference in magnitude between the said fifth control voltage and the said sixth control voltage; and fourth control means for applying said first resultant synchronization control voltage to one of said first and second differential control motors so as to control the instantaneous angular position ofthe input of the differential controlled by said o-ne of said first and second differential control motors in relation to the output thereof so as to control the instantaneous angular position of the corresponding one of said first and second rotating members in a manner whereby the said first and second rotating members are maintained in synchronism.

5. A circuit arrangement for the synchronization and speed control of rotating members, comprising, in combination, a first rotating member; a first D.C. driving motor; first transmission means including a first differential adapted to be controlled by a motor and coupling said first rotating member to said first driving motor, said first differential having an input coupled to said first driving motor and an output coupled to said first rotating member; a first differential control motor coupled to and controlling the instantaneous angular position `of the input of the first differential of said first transmission means in relation to the output thereof; a second rotating member; a second D.C. driving motor; second transmission means including a second differential adapted to be controlled by a motor and coupling said second rotating member to said second driving motor, said second differential having an input coupled to said second driving motor and an output coupled to said second rotating member; a second differential control motor coupled to and controlling the instantaneous angular position of the input of the second differential of Asaid second transmission means in relation to the output thereof; a first DC. generator connected to and energizing said first driving motor; a first A.C. motor coupled to and driving said first D.C. generator; a second D.C. generator connected to and energizing said second driving motor; a second A.C. motor coupled to and driving said second D.C. generator; first speed indicating means for providing a first control voltage having a magnitude proportional to the angular velocity of said first driving motor; second speed indicating means for providing a second control voltage having a magnitude proportional to the angular velocity of said second driving motor; means for providing a reference voltage of selected magnitude; first comparing means for comparing said rst control voltage and said reference voltage for producing a first resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said first control voltage and the said reference voltage; first control means lfor applying 161 said first resultant speed control voltage to said first generator so as to control the energzation and angular velocity of said first driving motor thereby controlling the angular velocity of said first rotating member; second comparing means for comparing said second control voltage and said reference voltage for producing a second resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said second control voltage and the said reference voltage; second control means for applying said second resultant speed control voltage to said second generator so as to control the energization and angular velocity of said second driving motor thereby controlling the angular velocity of said second rotating member; third speed indicating means for providing a third control voltage having a magnitude proportional to the angular velocity of said first rotating member; fourth speed indicating means for providing a fourth control voltage having a magnitude proportional to the angular velocity of said second rotating member; third comparing means for comparing said third control voltage and said fourth control voltage for producing a third resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said third control voltage and the said fourth control voltage; third control means for applying said third resultant speed control voltage to one of said first and second generators so as to control the energization and angular velocity of the corresponding one of said first and second driving motors thereby controlling the angular velocity of a corresponding one of said first and second rotating members; first angular position indicating means for providing a fifth control voltage having a magnitude proportional to the instantaneous angular position of said first rotating member, said first angular position indicating means comprising a first disc adapted to rotate synchronously with said first rotating member and having an angular position indicating marking thereon, first photosensitive means, and means for impinging light upon said first disc in a manner whereby light is refiected from said last-menltioned angular position indicating marking to said first photosensitive means; second angular position indicating means for providing a sixth control voltage having a magnitude proportional to the instantaneous angular position of said second rotating member, said second angular position indicating means comprising a first disc adapted to rotate synchronously with said second rotating member and having an angular position indicating marking thereon, second photosensitive means, and means for impinging light upon said second disc in a manner whereby light is refiected from said last-mentioned angular position indicating marking to said second photosensitive means; fourth comparing means for comparing said fifth control voltage and said sixth control voltage for producing a first resultant synchronization control voltage having a magnitude proportional to a difference in magnitude between the said fifth control voltage and the said sixth control voltage, said fourth comparing means comprising integrator means having inputs and outputs for providing an output voltage proportional to the amplitude and direction of a difference in magnitude between said fifth control voltage and said sixth control voltage, means for applying said fifth and sixth control voltages to the inputs of said integrator means, and means for deriving said first resultant synchronization control voltage from the outputs of said integrator means; and fourth control means for applying said first resultant synchronization control voltage from the outputs of said integrator means to one of said first and second differential control motors so as to control the instantaneous angular position of the input of the differential controlled by said one of said first and second differential control motors in relation to the output thereof so as to control the instantaneous angular position -of the corresponding one of said first and second rotating members in a manner whereby the said 11 first and second rotating members are maintained in synchronism.

6. A circuit arrangement for the synchronization and speed control of rotating members comprising, in combination, a first rotating member; a first D.C. driving motor; first transmission means including a first differential adapted to be controlled by a motor and coupling said first rotating member to said first driving motor, said first dierential having an input coupled to said first driving motor and an output coupled to said first rotating member; a first differential control motor coupled to and controlling the instantaneous angular position of the input of the first differential of said first transmission means in relation to the output thereof; a second rotating member; a second D.C. driving motor; second transmission means including a second differential adapted to be controlled by a motor and coupling said second rotating member to said second driving motor, said second differential having an input coupled to said second driving motor and an output coupled to said second rotating member; a second differential control motor coupled to and controlling the instantaneous angular position of the input of the second differential of said second transmission means in relation to the output thereof; a first D.C. generator connected to and energizing said first driving motor; a first A.C. motor coupled to and driving said first D.C. generator; a second D.C. generator connected to and energizing said second driving motor; a second A.C. motor coupled to and driving said second D.C. generator; first speed indicating means for providing a rst control voltage having a magnitude proportional to the angular velocity of said first driving motor; second speed indicating means for providing a second control voltage having a magnitude proportional to the angular velocity of said second driving motor; means for providing a reference voltage of selected magnitude; first comparing means for comparing said first control voltage and said reference voltage for producing a first resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said first control voitage and the said reference voltage; first controll means for applying said first resultant speed control voltage to said first generator so as to control the ener gization and angular velocity of said first driving motor thereby controlling the angular velocity of said first rotating member; second comparing means for comparing said second control voltage and said reference voltage for producing a second resultant speed control voltage having a magnitude proportional to a difference in magnitude between the said second control voltage and the said reference voltage; second control means for applying said second resultant speed control voltage to said second generator so as to control the energization and angular velocity of said second driving motor thereby controlling the angular velocity of said second rotating member; third speed indicating means for providing a third control voltage having a magnitude proportional to the angular velocity of said first rotating member; fourth speed indicating means for providing a fourth control voltage having a magnitude proportional to the angular velocity of said second rotating member; third comparing means for comparing said third control voltage and said fourth control voltage for producing a third resultant speed control voltage having a magnitude proportional to a difference in magnitude between the 12 said third control voltage and the said fourth control voltage; third control means for applying said third resultant speed control voltage to one of said first and second generators so as to control the energization and. angular velocity of the corresponding one of said first and second driving motors thereby controlling the angular velocity of a corresponding one of said first and second rotating members; first angular position indicating means for providing a fifth control voltage having a magnitude proportional to the instantaneous angular position of said fir-st rotating member, said first angular position indicating means comprising a first disc coaxially mounted on said first rotating member and rotating with said first rotating member and having an angular position indicating marking thereon, first photosensitive means, and means for impinging light upon said first disc in a manner whereby light is reflected from said last-mentioned angular position indicating marking to said first photosensitive means; second angular position indicating means for providing a sixth control voltage having a magnitude proportional to the instantaneous angular position of said second rotating member, said second angular position indicating means comprising a first disc coaxially mounted on said second rotating member and rotating with said second rotating member and having an angular position indicating marking thereon, second photosensitive means, and means for impinging light upon said second disc in a manner whereby light is reflected from said last-.mentioned angular position indicating marking to said second photosensitive means; fourth comparing means for comparing said fifth control voltage andv said sixth control voltage for producing a first resultant synchronization control voltage having a magnitude proportional to a difference in magnitude between the said fifth control voltage and the said sixth control voltage, said fourth comparing means comprising integrator means having inputs and outputs. for providing an output voltage proportional to the amplitude and direction ofA a difference in magnitude between said fifthY control voltage and said sixth control voltage, means for applying said fifth and sixth control voltages to the inputs of said integrator means, and means for deriving said first resultant synchronization control voltage from the outputs of said integrator means; and fourth control means for applying said first resultant synchronization control voltage from the outputs of said integrator means to one of said first and second differential control motors so as to control the instantaneous angular position of the input of the differential controlled by said one of f saidv first and second differential control motors in rela- -tion to the output thereof so as to control the instantaneous angular position of the corresponding one of said first and second rotating members in a manner whereby the said first and second rotating members are maintained in synchronism.

References Cited in the4 file of this patent UNITED STATES PATENTS 2,451,946 munisr -..p oct. 19, 194s 2,760,137 Andrewsl Aug. 2l, 1956 FOREIGN PATENTS 175,947 Austria Aug. 25, 1953 www-; wir w 

1. A CIRCUIT ARRANGEMENT FOR THE SYNCHRONIZATION AND SPEED CONTROL OF ROTATING MEMBERS, COMPRISING, IN COMBINATION, FIRST AND SECOND ROTATING MEMBERS; A FIRST DRIVING MOTOR COUPLED TO AND DRIVING SAID FIRST ROTATING MEMBER; A SECOND DRIVING MOTOR COUPLED TO AND DRIVING SAID SECOND ROTATING MEMBER; MEANS FOR PROVIDING A FIRST CONTROL VOLTAGE HAVING A MAGNITUDE PROPORTIONAL TO THE ANGULAR VELOCITY OF SAID FIRST DRIVING MOTOR; MEANS FOR PROVIDING A SECOND CONTROL VOLTAGE HAVING A MAGNITUDE PROPORTIONAL TO THE ANGULAR VELOCITY OF SAID SECOND DRIVING MOTOR; MEANS FOR PROVIDING A REFERENCE VOLTAGE OF SELECTED MAGNITUDE; MEANS FOR CONTROLLING THE ANGULAR VELOCITY OF SAID FIRST DRIVING MOTOR IN ACCORDANCE WITH A DIFFERENCE IN MAGNITUDE BETWEEN SAID FIRST CONTROL VOLTAGE AND SAID REFERENCE VOLTAGE THEREBY CONTROLLING THE ANGULAR VELOCITY OF SAID FIRST ROTATING MEMBER; MEANS FOR CONTROLLING THE ANGULAR VELOCITY OF SAID SECOND DRIVING MOTOR IN ACCORDANCE WITH A DIFFERENCE IN MAGNITUDE BETWEEN SAID SECOND CONTROL VOLTAGE AND SAID REFERENCE VOLTAGE THEREBY CONTROLLING THE ANGULAR VELOCITY OF SAID SECOND ROTATING MEMBER; MEANS FOR CONTROLLING THE ANGULAR VELOCITY OF ONE OF SAID FIRST AND SECOND DRIVING MOTORS IN 